JP2000304059A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the torque fluctuation and the scattering or evaporation of a lubricant with a low torque to reduce the cost by pressing and fixing inner and outer rings into a shaft and a housing, and providing a caulking part having a substantially V-shaped side sectional profile on a sealing plate between the inner and outer rings. SOLUTION: A ball bearing 1 comprises an inner ring 2 having an inside diameter 3 pressed in and fixed to a shaft 16, an outer ring 5 having an outer diameter 6 pressed in and fixed to a housing 17, and a sealing plate 9 between the inner and outer rings 2, 5, and the sealing plate 9 has a shield structure having a bottom part 10 closely fitted to the inside wall 13 of an outer ring seal groove and a caulking part 11 having a substantially V-shaped vertical side sectional profile to be elastically pressed onto a groove bottom 14. Since the radial reaction of the sealing plate 9 after the caulking by the sealing plate 9 can be weakened, and its direction can be set to the axial direction, the outer diameter circularity of the outer ring can be improved. Accordingly, the torque fluctuation by the influence of circularity can be minimized, and the leak of grease base oil by slippage or rotation can be minimized. Further, since the inner and outer rings are pressed in without using any adhesive, the outgassing by the adhesive can be eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing device used for a part that swings at a high speed and minutely, such as a swing arm bearing used for a magnetic disk drive.

[0002]

2. Description of the Related Art Recently, magnetic disk drives have been required to have higher densities. For this reason, the width of the track for recording signals on the disk is becoming increasingly narrower, and the swing arm equipped with a head for recording and reproducing signals has faster access to the target track and higher positioning performance. Is required. Therefore, the ball bearing supporting the swing arm is required not to have a torque fluctuation such as a low torque spike (rapid torque fluctuation) in order to satisfy a higher speed control and a higher accuracy.

[0003] Further, as the spacing between the head and the disk becomes smaller, a lubricant, a lubricating method and a fixing method with less scattering and evaporation are required for the ball bearing than ever before.

[0004] For example, in a conventional swing arm bearing device, two ball bearings 100 and 200 in which grease is sealed are used by applying a preload to the ball bearings. A general iron shield (such as a root shield) is used as shown. 301 in the figure
Indicates a swaged portion of the shield 300.

[0005] Also, the inner diameter surfaces 103 and 203 of the inner rings 101 and 201 and the outer diameter surfaces 10 and 203 of the outer rings 102 and 202, respectively.
4, 204 is coated with an adhesive and fixedly adhered to the shaft 400 or the housing 500 (FIGS. 4 and 5).

[0006]

However, conventionally, in a ball bearing for a swing arm, grease is used as a lubricant, and a general root shield shown in FIG. It was necessary to pay attention to the suppression of torque fluctuation and base oil seepage due to movement.

The inner rings 101 and 201 and the outer ring 10
Since the base members 2202 are bonded and fixed, there is a problem that outgas due to the adhesive does not adhere to the surface of the magnetic disk.

The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to provide a low torque, a small torque fluctuation, a small scattering and evaporation of a lubricant, An object of the present invention is to provide a low-cost rolling bearing device that does not cause outgassing due to an agent.

[0009]

According to the present invention, there is provided a rolling bearing, wherein inner and outer rings of a rolling bearing are press-fitted and fixed to a shaft and a housing, respectively, and are disposed between the inner and outer rings of the bearing. The sealing plate includes a caulking portion formed in a substantially U-shape in a sectional side view.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the present invention, and this embodiment will be described with the illustrated rolling ball bearing.
However, the present invention is not limited thereto, and other well-known structures such as a roller bearing can be applied within the scope of the present invention.

In each of the ball bearings 1, 1, the inner diameter 3 of the inner ring 2 is
6, the outer diameter 6 of the outer race 5 is press-fitted and fixed to the housing 17, respectively. In the drawing, reference numeral 8 denotes a rolling element (ball), and 9 denotes a sealing plate.

The interference at the time of press-fitting is 1 μm in diameter.
It is preferably at least 12 μm. If it is smaller than 1 μm, there is a risk of movement, and if it exceeds 12 μm, the rail wheel is greatly deformed, which may cause torque fluctuation.

The preload applying method may be a so-called resonance press-fitting method (resonance management) in which the inner ring 2 is press-fitted while being vibrated, and the outer ring 5 is pre-pressed while measuring the resonance frequency, or the inner ring 2 is vibrated. A so-called torque press-fitting method (torque management) may be adopted in which preload control is performed while measuring torque on the outer ring 5 side while press-fitting.

In the resonance press-fitting method, the resonance frequency is made constant. That is, although the rigidity can be made constant, the torque tends to vary to some extent. Conversely, the torque press-fitting method can make the torque constant, but on the other hand,
The resonance frequency (rigidity) tends to vary to some extent. Therefore, it is preferable to use the press-fitting method depending on whether resonance (rigidity) or torque is emphasized.

In any case, both the inner and outer rings 2 and 5 have the shaft 16
In addition, since it is press-fitted and fixed to the housing 17, the problem of outgas generation due to the adhesive is eliminated.

FIGS. 2 and 3 show one embodiment of a sealing plate (shield) 9 which is elastically crimped to the outer ring 5 side of the rolling ball bearing 1 and is disposed between the inner and outer rings 2, 5. In this embodiment, one end of the sealing plate 9 is fixed to the outer ring 5 side. However, the type is particularly limited as long as one end of the sealing plate 9 is fixed to one of the inner and outer rings by caulking. is not.

The sealing plate 9 is formed on the inner wall 1 of the outer ring seal groove 12.
The bottom surface portion 10 is in close contact with the bottom surface portion 3 and extends obliquely toward the groove bottom 14 of the outer ring seal groove 12 following the bottom surface portion 10 and is elastically press-fitted to the groove bottom 14 into a substantially rectangular shape in a vertical side view. A shield configuration including the formed caulked portion 11 is adopted. In addition, the shape to be illustrated is merely an example of the embodiment, and is not limited in any way, and can be appropriately changed within the scope of the present invention.

On the other hand, the seal groove 12 formed in the outer race 5 is provided at an inner wall 13 provided near the rolling element 8 and at an obtuse angle toward the end face 7 following the inner wall 13. A groove bottom 14 and an outer wall 15 formed at an obtuse angle following the groove bottom 14 are formed.

The use of the sealing plate (shield) 9 of the present configuration can reduce the radial reaction force of the sealing plate 9 after caulking due to the shape of the caulking portion 11 as viewed from the side, and Since the direction in which the reaction force acts can be directed more axially than the conventional root type shield, the outer ring outer diameter roundness can be further improved.

In addition, this eliminates the need for caulking while paying attention to the rear ellipse, so that the sealing plate 9 does not come off or rotate due to too weak caulking.

It is preferable to apply an oil repellent to at least one end face (outer end face) 4, 7 of the inner and outer rings 2, 5. By doing so, the clearance between the sealing plate 9 and the inner ring 2
The lubricating oil that oozes out from the minute clearance at the fixed portion between the sealing plate 9 and the outer ring 5 is repelled by the oil repellent, and can be prevented from leaking to the outside of the bearing. Note that the oil repellent may be applied to the entire surface of the sealing plate 9 or the seal groove bottom 14.

Since the ball bearing 1 of this configuration is press-fitted and fixed to the shaft 16 and the housing 17, further improvement in the outer ring outer diameter roundness reduces the deformation of the track wheel and lowers torque fluctuation. I can do it. In addition, it is not necessary to pay attention to the suppression of seepage of the base oil due to the detachment or rotation of the sealing plate (shield) 9.

[0023]

The present invention has a structure as described above, and uses a sealing plate provided with a crimped portion formed in a U-shape. It is possible to obtain a rolling bearing in which the torque fluctuation due to the influence of the roundness of the outer ring outer diameter can be reduced, and the bleeding of the grease base oil due to detachment and rotation is small.

Further, since the inner and outer races are press-fitted and fixed without using an adhesive, outgas due to the adhesive is eliminated, and there is no problem of contamination of the magnetic disk surface by the outgas. It is most suitable for a rolling bearing device used for a portion, for example, a ball bearing for a swing arm of a magnetic disk device.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a rolling bearing device of the present invention.

FIG. 2 is a longitudinal sectional view of a sealing plate used in the present invention.

FIG. 3 is a longitudinal sectional view of a crimped portion.

FIG. 4 is a longitudinal sectional view of a conventional technique.

FIG. 5 is a longitudinal sectional view of a sealing plate used in the prior art.

[Explanation of symbols]

 1: rolling ball bearing 2: inner ring 5: outer ring 8: rolling element 9: sealing plate (shield) 11: caulked portion 12: seal groove 17: shaft 18: housing

Claims (1)

[Claims] 1. An inner and outer ring of a rolling bearing is press-fitted and fixed to a shaft and a housing, respectively. A rolling bearing device, comprising: